The goal of this project is to design a new type of bedside incentive spirometer to help minimize respiratory complications, such as pneumonia and atelectasis, among postoperative patients. The bedside incentive spirometers in current widespread use in hospitals have several severe shortcomings, including inadequate patient feedback, no reminder mechanism to prompt their use by patients, and no means for physicians and nurses to assess patient breathing performance and treatment compliance. In this project, we will design a digital interactive bedside incentive spirometer, based on physician, nurse, and patient input, which avoids these drawbacks by incorporating an enhanced feature set and user interface design. Our central hypothesis is that our new incentive spirometer will improve patient breathing performance and treatment compliance and be more informative and useful to physicians and nurses, compared with current bedside incentive spirometers. The rationale for this project is that greater patient compliance will reduce postoperative respiratory complications, shorten the duration of postoperative hospitalization, and minimize the need for rehospitalization for respiratory compromise, all of which enhance patient welfare and reduce healthcare costs. We will accomplish project objectives by addressing three specific aims: 1) To develop design specifications for a prototype incentive spirometer. This prototype spirometer will be easy for patients to learn, use, and understand, while enabling physicians and nurses to accurately assess patient breathing performance, adherence to prescribed treatment, and breathing performance trends over time. The applied science of human factors engineering will be used to define user needs and requirements and to develop prototype design concepts and specifications. 2) To evaluate the ease of use of the prototype spirometer by constructing several low-fidelity prototype models and assessing their feature sets and interface designs so that areas of improvement can be identified. Healthcare providers will play a vital role in the design and test process by identifying needed healthcare features and evaluating prototype interface design. 3) Based on the results of the usability evaluations, we will refine the design specifications of the prototype spirometer to maximize its effectiveness and ease of use. The outcome of this effort will be a detailed and tested design specification and a prototype spirometer that is based on human factors engineering principles and physician, nurse, and patient input. This prototype device will significantly improve patient breathing performance and treatment adherence relative to incentive spirometers in current widespread use. It will also enable physicians and nurses to directly assess patients' breathing performance and adherence. This new spirometer is expected to have an important positive impact on patients' well-being by reducing the incidence and severity of postoperative respiratory complications. Given the widespread use of incentive spirometry among postoperative patients, the commercial potential and impact on patient outcome of this device is significant.